1. Field of Use
The invention pertains to a graft design that combines the minimal size and increased flexibility in its deliverable form which allows for successful navigation of torturous, stenotic blood vessels, aneurysms and other body passages with an in situ increase in size and rigidity, thus improving upon the current covered stent in treatment of various diseases such as atherosclerosis and aneurysms. The invention can be utilized in both the cerebral or peripheral circulatory system.
2. Prior Art
Inflatable devices for opening stenotic blood vessels are known. Devices such as angioplasty balloons, however, are unsuitable for permanent placement since the balloon component is fused to the catheter. Removal of the catheter will cause the collapse of the balloon. Further, the balloon itself may obstruct the lumen of the artery. Further, the procedure usually requires two separate steps; the first clearing of the occlusion and, second, the placement of a reinforcing stent with increased risk of embolization and the risk of restenosis. Currently metallic stents covered with a membrane are often installed as the second step.
Devices for treatment of aneurysms may not provide sufficient wall support or, alternatively, have material properties hindering their deployment within the affected portion of a vessel. Other devices may be subject to dislocation by the mechanics of fluid flow and pressure. Further, other devices of treating aneurysms, such as coils, are not suitable for certain types of aneurysms, e.g., wide neck or fusiform aneurysms. They may also be subject to incomplete olbitration of the aneurysm or coil compaction which may result in re-growth of the aneurysm and future rupture. Devices that are of a braid type construction are subject to variations of the longitudinal length in relation to radial expansion.